2026-05-02 · gigatonnes carbon in permafrost
Permafrost locks twice atmospheric carbon
Frozen soil in the Arctic stores ancient carbon. Thaw could rewrite the methane budget.
The Arctic's frozen ground holds roughly twice as much carbon as the entire atmosphere — an estimated 1,500–1,700 gigatonnes against about 850. If thaw unlocks it, ancient carbon could re-enter the air as CO₂ and methane, rewriting the methane budget. This grid sets the two stocks side by side.
1 cell = 1.7 gigatonnes carbon in permafrost (0.1% of permafrost carbon stock) · 1,000 cells
Context
The comparison pairs two carbon stocks: an estimated 1,500–1,700 gigatonnes of carbon locked in Arctic permafrost soil versus roughly 850 gigatonnes in the entire atmosphere. Figures follow Schuur et al. as assessed in the IPCC Sixth Assessment Report (Working Group I, 2021), with the grid taking the upper estimate, 1,700 gigatonnes, as its whole for the 2026 edition.
Permafrost carbon has accumulated over millennia and stays out of the climate system only while the ground remains frozen. As the Arctic thaws, long-stored organic matter can break down into carbon dioxide and methane — a feedback that could add warming on top of human emissions.
The wide range reflects how difficult it is to measure carbon across vast, unevenly frozen terrain. Even the low end, about 1,500 gigatonnes, outweighs the atmosphere's load, which is why permafrost sits within AR6's assessment of carbon-cycle feedbacks (Chapter 5).
Schuur et al. / IPCC AR6: permafrost ~1,500–1,700 Gt C vs ~850 Gt in atmosphere.
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Credit this grid as Inagrid — https://inagrid.com/e/2026-05-02-permafrost-carbon